SOME OBSERVATIONS ON THE SIZE AND SHAPE OF LICHEN ASCOSPORES IN RELATION TO ECOLOGY AND TAXONOMY

S ummary The length, breadth and volume of a large sample of ascospores from lichenized and non‐lichenized ascomycetes were compared and found to be approximately log‐normally distributed. Lichen ascospores were also classified into sizes and types and their distribution in relation to the substratum colonized was analyzed using x 2 . The distributions were found to be heterogeneous with certain spore types and sizes more frequent on some substrata than others. These results are discussed with reference to the survival, germination and atmospheric dispersal of ascospores. Ascospore length and breadth was measured in a single plant of Opegrapha chevallieri Leight. (Loculoascomycetes) and found to be normally distributed. Taxonomic implications are considered.